Device for forming cutting blade for prints

ABSTRACT

A device for forming a cutting blade for prints is disclosed. The device of this invention forms cutting blades by appropriately bending and cutting a metal strip into desired blades through integrated work regardless of a difference in the size of metal strips. The device is also provided with changeable jigs, thus being capable of forming bridge notches having different intervals, widths and configurations. The device has one vertically movable bending pin and one swing cutter. The bending pin is capable of quickly bending a metal strip into a desired configuration, while the swing cutter finely and precisely cuts the metal strip into cutting blades. The device also quickly produces high precision cutting blades, thus improving productivity and reducing the cost of the cutting blades.

TECHNICAL FIELD

[0001] The present invention relates, in general, to a device forforming a cutting blade for prints and, more particularly, to a devicecapable of forming such a cutting blade by appropriately bending andcutting a metal strip into desired blades through integrated workregardless of a difference in the size of metal strips.

BACKGROUND ART

[0002] In order to produce various flat prints or printed packingmaterials, such as paper boxes or thermoplastic films, it is necessaryfor flat prints or films to be cut along a designed cutting line, andfor box-shaped packing materials to be cut along a designed cutting lineof a printed paper board prior to forming the board into a box.

[0003] Such a cutting process for producing flat prints, paper boxes, orthermoplastic films has to be performed using a single-edged cuttingblade which extends along a desired cutting line. Such a cutting bladeis set on a flat wood block in a way such that the blade has a uniformheight. In such a case, the sharpened surface of the single edge of theblade faces outward. The wood block, with the cutting blade, isinstalled on a press, which is used for cutting such flat prints orpacking materials.

[0004] Typical cutting blades are produced by cutting a thin specialsteel strip into pieces. Such a steel strip has a band-shapedconfiguration and is sharpened at one edge prior to being subjected tothe bending and cutting processes. Such a metal strip has to be bent andcut into cutting blades which individually form a designed cutting linealong which flat prints or packing materials are cut by the cuttingblade. After the metal strip is bent and cut into cutting blades, one ormore cutting blades are set on a wood block. Therefore, it is primarilynecessary to precisely bend and cut the metal strip into cutting blades.In addition, the metal strip is also processed through a plurality ofsub-processes as follows.

[0005] For example, the metal strip has to be regularly notched at thelower edge opposite to the sharpened edge, thus forming bridge notchesat the lower edge. Such bridge notches are for firmly holding theposition of a cutting blade when the blade is set on a wood block. Thatis, the bridge notches almost completely prevent the set position of thecutting blade on the wood block from being unexpectedly deformed due toexternal impact. Sometimes, it is necessary to form a plurality ofV-notches along the sharpened edge of the metal strip, thus form acutting blade which is preferably used for forming perforated lines onprints, such as stamps. Sometimes, the metal strip may be bent at rightangles. In such a case, a bending slot has to be transversely formed ona side surface of the metal strip prior to bending the metal strip atright angles. When the metal strip has to be precisely bent, it ispreferable to bend the metal strip manually rather than mechanically andthis forces the metal strip to be subjected to a marking process offorming bending points on the metal strip prior to manually bending themetal strip.

[0006] Of course, the above-mentioned sub-processes of forming bridgenotches, V-notches, bending slots and bending points are well known tothose skilled in the art. However, in known blade forming devices, suchprocesses are not performed through integrated work, but are separatelyand selectively performed, so that the known devices fail to achievedesired precision and reduce productivity, and increase the productioncost of the cutting blades.

[0007] In the known devices, the process of cutting the metal strip intodesired cutting blades is separately performed from the abovesub-processes, thus more reducing productivity and increasing theproduction cost of the cutting blades.

[0008] In an effort to overcome such problems, a long metal strip, witha sharpened edge, may be wound around a feeding roll so as to beforcibly and continuously fed from the roll to a bending nozzle. At aposition around the bending nozzle, the metal strip comes into contactwith a plurality of bending pins which are used for bending the metalstrip into a desired configuration.

[0009] As well known to those skilled in the art, such a bendingprocess, using a bending pin, is numerically controlled by a computer.That is, a plurality of bending pins are positioned around the bendingnozzle and are precisely rotated in opposite directions in response tocontrol signals output from the computer, thus bending the metal stripcoming out from the bending nozzle. Such a bending process may bereferred to, for example, in Japanese Patent Laid-open Publication No.Heisei. 899,123.

[0010] In the typical blade forming devices, the metal strip may be cutinto a plurality of pieces, having designed lengths, before the metalstrip reaches the bending nozzle. In a brief description, the metalstrip may be cut into pieces before a bending process. Alternatively,the metal strip may be cut into pieces after a bending process asdisclosed in Japanese Patent Laid-open Publication No. Heisei.8-243,834. In this Japanese Patent, the metal strip, coming out from thebending nozzle, is repeatedly bent in opposite directions until S themetal strip is cut due to fatigue fracture.

[0011] However, the typical blade forming devices are problematic inthat they fail to produce high quality cutting blades and cannot producethe cutting blades through integrated work.

[0012] That is, the configuration of the bridge cutting jig, installedin the typical devices, is fixed, so that it is almost impossible tochange the intervals or configuration of the bridge notches of the metalstrip. In addition, the typical devices have to separately perform amachining process of forming such bridge notches on the metal strip, sothat the devices reduce productivity and increase the production cost ofthe cutting blades.

[0013] Another problem of the typical blade forming devices is caused bythe bending pins used for bending the metal strip into a desiredconfiguration. That is, the bending pins have to be held by a complexholding means, thus complicating the construction of the cutting bladeforming device. In addition, it is almost impossible to precisely adjustthe bending angle of the bending pins without causing error.

[0014] When the metal strip is subjected to a bending process after acutting process, the cutting blades have accumulative error during thebending process, so that the cutting blades have a low precision.

[0015] In addition, when at least one of the bending pins isfrictionally abraded, it is almost impossible to precisely center thebending pins. In such a case, the bending pins have to be repositionedone by one and this reduces work efficiency while bending the metalstrip.

[0016] During a bending process using the typical device, the sharpenededge of the metal strip comes into contact with the bending pins, sothat the sharpened edge may be damaged.

[0017] The most important problem, experienced in the typical bladeforming devices, is caused during a cutting process. That is, since themetal strip from a bending process is cut into pieces by repeatedlybending the metal strip in opposite directions until the metal strip iscut due to fatigue fracture, the edge, along which the metal strip iscut, is not smooth, but is exceedingly rough with burrs, thus spoilingthe appearance of the cutting blades. In order to remove such burrs fromthe cutting blades, the blades have to be subjected to an additionalgrinding process. In addition, after the metal strip is cut into pieces,it is necessary to finally machine the pieces so as to produce resultingblades and this forces the metal strip to be cut into pieces withmachining allowance. Due to such machining allowance, it is almostimpossible to produce high precision blades.

[0018] Therefore, it is preferable to perform the processes of formingthe bridge notches on a metal strip, bending the metal strip into adesigned configuration and cutting the metal strip into cutting bladesthrough integrated work while precisely adjusting the bending angle ofthe bending pins and finely cutting the metal strip into cutting blades.In such a case, the cutting blades from the cutting process may be freefrom any additional machining process.

[0019] In addition, it is necessary for the blade forming devices to beflexibly used for processing metal strips having different sizes. Theblade forming devices also have to be designed for effectively bendingthe metal strips into different configurations when necessary.

DISCLOSURE OF THE INVENTION

[0020] Accordingly, the present invention has been made keeping in mindthe above problems occurring in the prior art, and an object of thepresent invention is to provide a device for forming a cutting blade forprints, which is provided with changeable jigs, thus being capable offorming bridge notches having different intervals and configurations,and which forms cutting blades by appropriately bending and cutting ametal strip into desired blades through integrated work regardless of adifference in the size of metal strips.

[0021] Another object of the present invention is to provide a devicefor forming a cutting blade for prints, which has one vertically movablebending pin and one swing cutter, the bending pin being capable ofquickly bending a metal strip into a desired configuration and the swingcutter finely and precisely cutting the metal strip into cutting blades.

[0022] A further object of the present invention is to provide a devicefor forming a cutting blade for prints, which quickly produces highprecision cutting blades, thus improving productivity and reducing thecost of the cutting blades.

[0023] In order to accomplish the above object, the present inventionprovides a device for forming a cutting blade for prints, comprising: astrip roll unit having a sufficient amount of metal strip and beingrotatable in a direction by intermittent drive means, thus supplying themetal strip at a constant rate; two guide blocks provided in front ofthe roll unit and adapted for guiding the metal strip from the rollunit; a bridge cutting mold detachably and selectively installed at oneside of the two guide blocks and used for forming bridge notches on themetal strip, the bridge cutting mold comprising: a housing having both astrip passing hole and a jig guide slot, the strip passing holeperpendicularly meeting the jig guide slot; and a spring-biased jigmovably positioned in the jig guide slot, thus selectively and quicklymovable in the jig guide slot so as to form the bridge notches on themetal strip passing through the strip passing hole; a guide bendingblock provided in front of the bridge cutting mold and having a bendingnozzle used for distributing the metal strip from the bridge cuttingmold; a guide bending pin vertically positioned in front of the bendingnozzle, the bending pin being vertically and controllably movable androtatable in opposite directions, thus bending the metal strip from thebending nozzle into a desired pattern; a carrier movably held by twovertical guide rails standing in front of the bending pin, the carrierbeing movable downward under the guide of the two guide rails by a firstcylinder actuator in response to a bending process ending signal; astrip holder mounted to a bottom center of the carrier and adapted forvertically holding the metal strip from the bending pin; a swing cutterhinged to the carrier and positioned in front of the strip holder, theswing cutter being selectively rotated by a second cylinder actuator inaccordance with a detected angle of the metal strip, thus beingpositioned at a cutting process waiting position; a table provided witha slot for selectively holding a lower end of the strip holder with thecarrier fully descending, the table also having a horizontal guidegroove in front of the slot; and a movable piece slidably set in thehorizontal guide groove of the table and having a locking slot at a topsurface, the movable piece being quickly movable in opposite directionsin the guide groove with a lower end of the cutter being held by thelocking slot of the movable piece, thus quickly cutting the metal stripinto cutting blades.

BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The above and other objects, features and other advantages of thepresent invention will be more clearly understood from the followingdetailed description taken in conjunction with the accompanyingdrawings, in which:

[0025]FIG. 1 is a perspective view of a blade forming device inaccordance with the preferred embodiment of the present invention;

[0026]FIG. 2 is a longitudinal sectioned view showing the constructionof the device of FIG. 1;

[0027]FIG. 3 is a perspective view showing a metal strip roll unit witha plurality of guide rollers being arranged at the front of the rollunit in accordance with the present invention;

[0028]FIG. 4 is a perspective view showing a bridge cutting mold and abridge cutting jig used in the device of this invention;

[0029]FIGS. 5A and 5B are views of typical bridge cutting jigs;

[0030]FIGS. 6A and 6B are views showing the operation and configurationof the bridge cutting jig used in the device of this invention;

[0031]FIGS. 7A to 7C are views showing the examples of bridge notchesformed on the sharpened edge of a metal strip by the bridge cutting jigof this invention;

[0032]FIG. 8 is a perspective view showing a grinding wheel used fortransversely forming a bending slot on a side surface of the metal stripin accordance with an embodiment of this invention;

[0033]FIG. 9 is a perspective view showing a bite used for transverselyforming a bending slot on a side surface of the metal strip inaccordance with another embodiment of this invention;

[0034]FIG. 10 is a plan view of a metal strip which is bent along abending slot at right angles in accordance with this invention;

[0035]FIG. 11 is a perspective view of a metal strip having a V-notch atthe sharpened edge in accordance with the invention;

[0036]FIGS. 12A to 12C are perspective views individually showing thelower edge of a metal strip, which is gradually deformed due to at leastone marking slot typically formed on the lower edge of the metal stripin order to form a bending point on the metal strip prior to manuallybending the metal strip;

[0037]FIG. 13 is a perspective view showing the operation of two markingjigs used for forming a plurality of bending points on both sidesurfaces of a metal strip in accordance with the present invention;

[0038]FIG. 14 is a perspective view showing the operation of a movablebending pin used for bending the metal strip into a desiredconfiguration in accordance with the invention;

[0039]FIG. 15 is a view showing the cross-section of the bending pin ofFIG. 14;

[0040]FIG. 16 is a perspective view of a first gear used for holding andoperating the bending pin of FIG. 14;

[0041]FIG. 17 is a perspective view showing the arrangement of first andsecond gears for the bending pin of this invention;

[0042]FIG. 18 shows an exploded perspective view showing top and bottomplates which are oppositely arranged on the device of this inventionwith a bending block being vertically positioned between the two plates;

[0043]FIG. 19 is a side view showing the front portion of the devicewith the bending block of FIG. 18;

[0044]FIG. 20 is a front view showing the front portion of the deviceprovided with both a strip holder and a swing cutter in accordance withthe invention;

[0045]FIG. 21 is a view showing the operation of both the strip holderand the swing cutter of FIG. 20;

[0046]FIG. 22 is a view showing the front portion of a table providedwith both the strip holder and the swing cutter of FIG. 20;

[0047]FIG. 23 is a perspective view of the strip holder of thisinvention;

[0048]FIG. 24 is a cross-sectioned view of the strip holder taken alongthe line A-A of FIG. 23;

[0049]FIG. 25 is a perspective view of the swing cutter of thisinvention;

[0050]FIG. 26 is a front view of the swing cutter of FIG. 25;

[0051]FIGS. 27A and 27b are views showing the operation of the swingcutter of this invention; and

[0052]FIG. 28 is a perspective view of a wood block provided with acutting blade produced by the device of this invention.

BEST MODE FOR CARRYING OUT THE INVENTION

[0053]FIG. 1 is a perspective view of the blade forming device inaccordance with the preferred embodiment of the present invention. FIG.2 is a sectional view showing the construction of the device of FIG. 1.

[0054] In accordance with the present invention, a metal strip 1, whichis the material of cutting blades and is previously sharpened at oneedge, is installed on the device 100 and is continuously fed to bendingand cutting units of the device as follows.

[0055] That is, a table 10 forms the base surface of the device 100 andis provided with a strip roll unit at an appropriate position. As shownin FIG. 3, the above roll unit comprises at least two rolls 50, whichare positioned aside each other and individually have a sufficientamount of metal strip 1. The above rolls 50 are operated by anintermittent drive means, such as a stepping motor 51, thus beingrotatable in a direction and feeding the metal strip 1 to a bridgecutting position at a constant rate.

[0056] The above rolls 50 are designed for being rotatable in oppositedirections, so that either of the rolls 50 smoothly feeds the metalstrip 1 to the bridge cutting position even when the metal strip 1 iswound around the rolls 50 in opposite directions. Since the strip rollunit of the device 100 comprises two or more rolls 50, it is possible toincrease the amount of metal strip 1 installed on the device 100 andallow differently sized metal strips 1 to be installed on the device 100at the same time when necessary.

[0057] In order to guide the metal strip 1 from either of the rolls 50to the bridge cutting position, two guide blocks 2 are provided in frontof the rolls 50 with a plurality of guide rollers 52 being arrangedbetween the two blocks 2. Due to the guide rollers 52, it is possible tofeed the metal strip 1 from either roll 50 to the mold 20 at apredetermined feeding rate.

[0058] During the operation of the device 100, a predetermined length ofthe metal strip 1 moves forward by the rotating force of the steppingmotor 51 under the guide of the guide blocks 2. When the strip 1 reachesthe bridge cutting position, a predetermined number of bridge notches 1a are formed on the lower edge of the strip 1. In order to form suchbridge notches 1 a, a bridge cutting mold 20 has to be installed on thedevice 100. In order to install the mold 20 on the device 100, one ofthe two guide blocks 2 is movable in order to form an opening forinstalling the bridge cutting mold 20 on the device 100. Alternately,the top of an external casing, covering the guide blocks 2, may beopened prior to installing the bridge cutting mold 20 onto the device100 from the top of the device 100.

[0059] Of course, it should be understood that the device 100 may beprovided with two or more openings for bridge cutting molds. In such acase, the openings for the bridge cutting molds are positionedapproximate to each other and seat two or more bridge cutting molds,having different functions, on the device 100 at the same time.

[0060] The casing for the guide blocks 2 comprises two plates: top andbottom plates 3, which are oppositely arranged on the device 100 with abending block 4 being vertically positioned between the two plates 3 asshown in FIGS. 18 and 19. Each of the two plates 3 has a longitudinalfitting channel 3 a at the inside surface, thus allowing the top andbottom sides of the bending block 4 to be held by the channels 3 a ofthe two plates 3. The above casing, comprising the two plates 3 and thebending block 4, is arranged on the device 100 in a way such that thebending block 4 is horizontally aligned with the strip outlet of the twoguide blocks 2.

[0061] The above bending block 4 has a bending nozzle 4 a at the frontend, so that the metal strip 1 from the bridge cutting mold 20 isinserted into the bending nozzle 4 a. In the present invention, thebending block 4 may be changed with another block 4 in accordance withthe size and configuration of the metal strip 1. That is, in the device100 of this invention, the bending block 4 is changeable, so that it ispossible to change the type of the bending nozzle 4 a in accordance withthe size and configuration of the metal strip 1. Such a changeablebending block 4 is also held by specified plates 3, so that it isnecessary for the plates 3 to be changed along with the bending block 4.

[0062] During the operation of the device 100, the metal strip 1 iscontinuously distributed from the bending nozzle 4 a of the block 4under the control of a numerical control program prior to being bent. Aguide bending pin 31 is movably positioned at a side of the front end ofthe bending block 4 in a way such that the pin 31 is vertically movable.The above pin 31 is held by two gears at the top and bottom ends and isrotatable in opposite directions by a reversible stepping motor 30.

[0063] In such a case, two removable compression rollers 60 and 60 a areprovided at appropriate positions relative to the guide blocks 2. In thepresent invention, it is preferable to position the two rollers 60 and60 a at the inlet and outlet of the guide blocks 2, respectively; Thetwo rollers 60 and 60 a press the leading portion of the metal strip 1at an appropriate pressure, thus allowing the metal strip 1 from theguide blocks 2 to move while maintaining a height.

[0064] Two guide rails 11, each having a predetermined length,vertically and oppositely stand at a position outside the bending nozzle4 a. A first cylinder actuator 41 is vertically positioned between thetwo guide rails 11. The first cylinder actuator 41 is operable inaccordance with a bending process ending signal. The piston of the aboveactuator 41 is coupled to a movable carrier 40, so that the carrier 40is vertically slidable under the guide of the two guide rails 11.

[0065] A strip holder 42 is screwed to the bottom center of the abovecarrier 40, so that the holder 42 is changeable with another one. Theabove strip holder 42 is vertically slitted upwardly from the lower end,thus having a vertical slit which has width and depth similar tothickness and width of the metal strip 1. A swing cutter 43 is hinged tothe carrier 40 and is positioned at the front of the above strip holder42 with a fine gap being formed between the cutter 43 and the holder 42.The above swing cutter 43 is operated by a second cylinder actuator 44which is horizontally positioned at a side of the carrier 40. The aboveactuator 44 operates the swing cutter 43 in accordance with a detectedangle of the metal strip 1 or a preset program. When the carrier 40descends under the guide of the rails 11, the strip holder 42 primarilyholds the metal strip 1. In such a case, the position of the stripholder 42 is fixed so as to almost completely prevent the metal strip 1from being moved during a cutting process. In order to fix the stripholder 42, a slot 45 is formed at the front end of the table 10. Ahorizontal guide groove 46 is formed at the front of the slot 45.Slidably set in the above guide groove 46 is a movable piece 48 whichhas a locking slot 47 at the top surface. The movable piece 48 holds thelower end of the swing cutter 43 at the locking slot 47. The abovemovable piece 48 is coupled to a cylinder actuator inside the table 10through a link motion, so that the piece 48 is movable to the left orright inside the guide groove 46. The swing cutter 43 is thus quicklyrotated in opposite directions by the second actuator 44 and finely cutsthe metal strip 1 into cutting blades.

[0066] As shown in FIG. 3, the guide rollers 52 consist of a pluralityof horizontal guide rollers 52 a and a plurality of vertical guiderollers 52 b. The above guide rollers 52 guide the metal strip 1 fromthe rolls 50 to the gap between the two guide blocks 2.

[0067]FIG. 4 is a perspective view showing the construction of a bridgecutting mold which is changeably set in the opening between the twoguide blocks 2. FIGS. 5A and 5B are sectional views of typical bridgecutting jigs, while FIGS. 6A and 6B are sectional views showing theconfiguration and operation of the bridge cutting jigs in accordancewith the present invention.

[0068] As shown in the drawings, the bridge cutting jig 21 of thisinvention is spring-biased and primarily inserted into the guide slot 20a of the bridge cutting mold 20 with both sides of the front edge 21 aof the jig 21 being held by the slot 20 a, so that the jig 21 is almostcompletely prevented from being unexpectedly moved inside the mold 20.Thereafter, the jig 21 is quickly and fully inserted into the mold 20.In such a case, the jig 21 smoothly slides while being separated fromthe side wall of the guide slot 20 a, thus being almost completely freefrom frictional abrasion. Therefore, the jig 21 of this invention iseffectively used for a lengthy period of time.

[0069] However, the typical bridge cutting jig has the followingproblem. When the typical jig is primarily inserted into the bridgecutting mold, neither side or only one side of the jig is inserted intothe guide slot 20 a of the mold 20, so that the jig has to be broughtinto frictional contact with the side wall of the slot 20 a when the jigis quickly and fully inserted into the mold 20. Therefore, the jig isexceedingly abraded or unexpectedly broken due to the frictionalcontact, so that it is impossible to use the jig for a lengthy period oftime.

[0070] The bridge cutting mold 20 of this invention is changeablyinstalled on the device, so that the bridge cutting mold 20 may befreely changed with another one in order to change the mold jig 21 withanother jig capable of forming the bridge notches 1 a having a desiredwidth. When repeatedly notching the metal strip 1 using a small-sizedjig 21 while precisely and finely moving the metal strip 1 through thebridge cutting mold 20, it is possible to form the bridge notches 1 a,having an enlarged width, on the metal strip 1.

[0071]FIGS. 7A to 7C are views showing the configuration of strips 1,with different bridge notches 1 b being formed along the sharpened edgeof the strip 1 by different jigs of this invention through a punchingprocess. In accordance with such a punching process using the jigs 21, aplurality of bridge notches 1 b, having a predetermined width, areformed along the sharpened edge of the strip 1.

[0072] For example, such a strip 1, with the bridge notches 1 b, ispreferably used for forming a perforated line on a printed material,such as tickets or receipts. Of course, it is possible to adjust the gapbetween the perforations of the perforated line by controlling thepunching interval of the jig during a punching process for the bridgenotches 1 b.

[0073] The device 100 of this invention is also provided with a unit fortransversely forming a vertical bending slot on a side surface of themetal strip. In accordance with the preferred embodiments of thisinvention, such a bending slot 1 d may be formed on a side surface ofthe metal strip 1 using a grinding wheel of FIG. 8 or a bite of FIG. 9.The construction and operation of the grinding wheel and the bite willbe described hereinbelow.

[0074]FIG. 10 is a plan view of a metal strip 1 which is bent at rightangles along a vertical bending slot 1 d. FIG. 11 is a perspective viewof a metal strip 1 having a plurality of regularly-spaced V-notches 1 con the sharpened edge, with one of the V-notches being shown in thedrawing.

[0075] As shown in FIG. 11, a plurality of V-notches 1 c may beregularly formed on the sharpened edge of the metal strip 1. A cuttingblade, with such V-notches 1 c, is preferably used for formingperforated lines on prints so as to form perforated paper or stamps withperforations being spaced at regular intervals of the V-notches 1 c.When it is necessary for the metal strip 1 with the V-notches 1 c to bebent at an acute or obtuse angle, a bending slot 1 d is instantaneouslyand transversely formed on a side surface of the metal strip 1 prior toprecisely bending the strip 1.

[0076] In order to form such a bending slot 1 d on the metal strip 1,the metal strip 1 is held by the guide blocks 2 in such a manner thatthe strip 1 is partially exposed outside the guide blocks 2 with amotor-operated up/down cylinder actuator 70 being positioned above adesired portion of the strip 1 as shown in FIG. 8. A stepping motor 71is mounted to the piston shaft of the above cylinder actuator 70 and isselectively activated in accordance with an up/down motion of the pistonshaft of the above cylinder actuator 70. A grinding wheel 72 is fixedlyfitted over the drive shaft of the stepping motor 71 and is used fortransversely forming such a bending slot 1 d on a side surface of thestrip 1. The above grinding wheel 72 is also used for forming theV-notches 1 c on the sharpened edge of the metal strip 1.

[0077] The above up/down cylinder actuator 70 is held by a supportcolumn 73 which integrally extends from the table 10 so as to bepositioned just above the guide blocks 2. The cylinder 70 is controlledby a control program.

[0078] The above stepping motor 71 is mounted to the piston shaft of thecylinder 70 at right angles, so that the motor-operated grinding wheel72 selectively forms the V-notches 1 c on the sharpened edge or thebending slot 1 d on the side surface of the metal strip 1.

[0079] Of course, such V-notches 1 c may be formed by a mold (notshown), having the same configuration as that of the V-notch 1 c, inplace of the grinding wheel 72. In such a case, the bending slot 1 d maybe formed by a separate cutting means.

[0080] In accordance with another embodiment of this invention, a bite74 is axially mounted to the up/down cylinder actuator 70 in place ofthe grinding wheel 72 as shown in FIG. 9. The above bite 74 transverselyforms a bending slot 1 d on a side surface of the metal strip 1 inaccordance with an up/down motion of the cylinder actuator 70.

[0081]FIGS. 12A to 12C show the lower edge of a metal strip which isgradually deformed due to marking slots formed on the lower edge of themetal strip in order to form a bending point on the strip in the priorart. FIG. 13 shows the operation of two marking jigs used for forming aplurality of bending points on both side surfaces of a metal strip inaccordance with the present invention.

[0082] As well known to those skilled in the art, a marking process isfor forming a bending point on a metal strip 1 prior to a manual bendingprocess. That is, when it is necessary to precisely bend a metal strip 1into a desired configuration, the bending process is not performed by abending machine, but is preferably performed manually. In order tomanually bend the metal strip 1, at least one bending point has to beformed on the strip 1 prior to performing a bending process. In theprior art, a marking slot is formed on the lower edge of the metal strip1 by a jig as shown in FIG. 12A, thus forming a bending point on thestrip 1. However, in the prior art, a plurality of marking slots may besometimes concentrated on the lower edge of the metal strip 1 as shownin FIGS. 12B and 12C and this allows the lower edge of the metal strip 1to be exceedingly deformed or distorted. However, such a problem isalmost completely overcome by the device of this invention which formstwo bending points on each side surface of the metal strip 1 by themarking jigs of FIG. 13. As shown in FIG. 13, two removable marking jigs80 and 80 a, individually operated in conjunction with a cylinderactuator, are positioned at both sides of the metal strip 1 so as to bedirected toward the strip 1. The two numerically controlled jigs 80 and80 a are selectively biased toward the metal strip 1 by biasing pins.The biasing pins are individually operated in conjunction with acylinder actuator, so that the biasing pins quickly push the jigs 80 and80 a onto both sides of the strip 1. Each of the two marking jigs 80 and80 a thus forms two bending points on each side surface of the metalstrip 1 without deforming or distorting the metal strip 1.

[0083]FIG. 14 is a perspective view showing the configuration of a guidebending pin used for bending the metal strip 1 into a desiredconfiguration in accordance with the present invention. FIG. 15 is aplan view showing the cross-section of the bending pin of FIG. 14. FIG.16 is a perspective view of a first gear with both the bending pin and apin protecting guide. FIG. 17 is a perspective view showing theoperation of the above bending pin.

[0084] As shown in FIGS. 2, 16 and 17, an opening, preferably, acircular opening 12, is formed on the table 10 at a position under thebending block 4. The first gear 33 with a bearing 32 is rotatablypositioned just under the opening 12, while a second gear 33 a with abearing 32 a is positioned above the opening 12 so as to be opposite tothe first gear 33.

[0085] The first and second gears 33 and 33 a individually have a pininsert hole 33 b at a corresponding position, while the bending pin 31is movably inserted into the pin insert hole 33 b of the first gear 33.Of course, the pin 31 is also inserted into the pin insert hole 33 b ofthe second gear 33 a, thus being movably held by the two gears 33 and 33a at the top and bottom portions. A pin guider 33 c, having both asemicircular cross-section and a height corresponding to the width ofthe metal strip 1, is provided at each of the pin insert holes 33 b. Thepin guiders 33 c of the two gears 33 and 33 a guide the verticalmovement of the bending pin 31 while protecting the pin 31 from beingunexpectedly bent or broken during a bending process.

[0086] As best seen in FIGS. 14 and 15, the bending pin 31 has aspecifically rounded cross-section or a generally semicircularcross-section with opposite side surfaces being convex and concave,respectively. The above bending pin 31 is positioned in a way such thatthe pin 31 comes into contact with the metal strip 1 at either ofopposite rounded corners between the convex and concave surfaces.

[0087] Two notches 31 a are formed along each rounded corner of the pin31. When the pin 31 comes into contact with the metal strip 1 during abending process, the two notches 31 a are positioned around the upperand lower edges of the metal strip 1, thus allowing the rounded cornerto be brought into close contact with the side surface of the metalstrip 1 at the intermediate portion between the two notches 31 a.Therefore, the bending pin 31 is free from giving any damage to thesharpened edge of the metal strip 1 when the rotating pin 31 pushes themetal strip 1 during a bending process.

[0088] Due to the above notches 31 a, the bending pin 31 uniformlypushes the metal strip 1 and is easily and precisely positioned relativeto the strip 1.

[0089] The lower end of the bending pin 31 is connected to the piston ofa cylinder actuator 34 which is fixed to the lower end of the first gear33, so that the pin 31 is movable upward by the cylinder actuator 34.That is, when the pin 31 is operated by the actuator 34, the pin 31 isprojected upward from the opening 12 and is inserted into the pin inserthole 33 b of the second gear 33 a. The bending pin 31 is thus firmlyheld by the two gears 33 and 33 a.

[0090] Sometimes, the pin insert hole 33 b of the second gear 33 a mayfail to be precisely aligned with the pin insert hole 33 b of the firstgear 33. In such a case, the position of the pin insert hole 33 b of thesecond gear 33 a has to be adjusted and this is easily accomplished byappropriately moving a gear box of the second gear 33 a to the front,back, left or right.

[0091] In order to allow the bending pin 31 to be rotatable in oppositedirections, the first and second gears 33 and 33 a are individuallyconnected to a drive gear 35 or 35 a of the reversible stepping motor 30through a belt. The two gears 33 and 33 a are thus rotatable at the samespeed and at the same time. The above stepping motor 30 is provided onthe bottom surface of the device 100 as described above. Of course, boththe motor 30 and the cylinder actuator 34 are operated under the controlof a computer.

[0092] When the metal strip 1 is distributed from the strip roll unitthrough the two guide blocks 2, the bending pin 31 is rotated inconjunction with the first and second gears 33 and 33 a at a positionaround the bending nozzle 4 a of the bending block 4, thus bending themetal strip 1 into a desired configuration. When it is necessary tochange the bending direction of the metal strip 1, the bending pin 31moves downward prior to changing the position of the bending pin 31relative to the metal strip 1. Thereafter, the bending pin 31 movesupward so as to come into contact with a selected surface of the metalstrip 1.

[0093] In such a case, since the bending block 4 is movably set on thedevice 100, it is possible to adjust the gap (a) between the bendingblock 4 and the bending pin 31 in accordance with the thickness of themetal strip 1. For example, when the metal strip 1 is relatively thinnerthan a reference strip, the bending block 4 moves forward so as toreduce the gap (a) between the bending block 4 and the bending pin 31.On the other hand, when the metal strip 1 is relatively thicker than thereference strip, the bending block 4 moves backward so as to enlarge thegap. Such a movement of the bending block 4 for adjusting the gap(a) maybe easily understood from FIGS. 18 and 19.

[0094]FIG. 20 is a front view of the device, showing both a strip holderand a swing cutter being used for holding and cutting the metal strip,respectively. FIG. 21 is a view showing the operation of both the stripholder and the swing cutter.

[0095] After the metal strip 1 is bent as described above, the metalstrip 1 is cut into cutting blades by the device as follows. is Themetal strip 1 from the bending process continuously moves to the frontportion of the table 10.

[0096] In such a case, a swing cutter 43 is moved to a desired cuttingposition where the cutter 43 cuts the metal strip 1 into cutting blades.The above swing cutter 43, which is positioned at the front of thebending block 4, is hinged to and rotatably held by the movable carrier40.

[0097] The above carrier 40 is slidably held by the two vertical guiderails 11 at both side edges and is operated in conjunction with thefirst cylinder actuator 41, thus selectively and vertically slidingalong the two rails 11 in opposite directions.

[0098] A removable strip holder 42, used for holding the metal strip 1,is provided at the lower edge of the carrier 40. FIGS. 23 and 24 areperspective and cross-sectioned views of the above strip holder 42,respectively.

[0099] The above strip holder 42 consists of two blocks, which have thesame configuration and form a strip holding slit 42 a between them whenthe two blocks are integrated into a single body. The above holder 42 isdesigned for adjusting the width of the strip holding slit 42 a inaccordance with the thickness of the metal strip 1.

[0100] That is, the strip holding slit 42 a of the holder 42 is formedbetween the inside surfaces of the two blocks. The inside end or the webof the strip holding slit 42 a is V-shaped, thus firmly holding thesharpened edge of the metal strip 1 without giving any damage to thesharpened edge of the strip 1. Both the above strip holder 42 and thebending block 4 form a set, so that the holder 42 is changeable alongwith the bending block 4.

[0101] The edge of the mouth of the strip holding slit 42 a ischamfered, so that it is possible to effectively guide the metal strip 1into the slit 42 a without failure even when the strip 1 from thebending nozzle 4 a fails to be precisely aligned with the slit 42 a.

[0102] In such a case, the swing cutter 43 is rotated by the secondcylinder actuator 44, thus being temporarily held in a cutting processwaiting position at a side of the strip holder 42 and moves downwardalong with the carrier 40 as shown in FIGS. 27A and 27B. In such a case,the movable piece 48, which is positioned in the front of the slot 45 ofthe table 10, horizontally moves so as to hold the lower end of theswing cutter 43 in the locking slot 47.

[0103] The swing cutter 43, which is firmly held by the locking slot 47of the movable piece 48, is allowed to precisely cut the metal strip 1.That is, when it is necessary to cut the strip 1 into cutting blades,the movable piece 48 is operated by the cylinder actuators, so that thepiece 48 slides in the guide groove 46 in opposite directions with theswing cutter 43 finely and precisely cutting the metal strip 1. Ofcourse, the swing cutter 43 may be moved to the bending process waitingposition under the control of a proximity or photo sensor, which checksthe finally bent portion of the metal strip 1 prior to outputting astart signal to the cylinder actuator for the cutter 43.

[0104]FIGS. 25 and 26 are views showing the configuration of the swingcutter 43 of this invention. As shown in the drawings, the lower portionof the cutter 43 narrows in the middle with an inclined cutting surface43 a, thus forming a narrow waist. The above cutting surface 43 a isinclined at an angle of B. When the swing cutter 43 is rotated so as tocut the metal strip 1, the cutter 43 primarily comes into contact withthe lower portion of the metal strip 1 at the cutting surface 43 a, sothat the cutter 43 cuts the metal strip 1 from the lower to the upperedge of the strip 1. Therefore, the swing cutter 43 finely andperpendicularly cuts the metal strip 1 without failure.

[0105] That is, when the metal strip 1 is cut from the upper to thelower edge by the swing cutter, the strip 1 is biased downward in thestrip holder 42 by the cutting force of the swing cutter 43, so that theholder 42 fails to firmly hold the strip 1 and this allows the strip 1to be unexpectedly and inclinedly cut. Meanwhile, when the metal strip 1is cut from the lower to the upper edge by the swing cutter 43 asdescribed above, the strip 1 is biased upward, thus being more firmlyheld by the strip holder 42 and being finely and perpendicularly cut atone time.

[0106]FIG. 29 is a view showing two or more cutting blades, which areproduced by the device of this invention and are set on a flat woodblock. As shown in the drawing, when two or more cutting blades are seton a wood block with ends of the blades closely meeting each other atright angles, a gap may be formed at the junction between the cuttingblades 1 due to the sharpened edges of the blades 1. That is, a gap maybe formed between one end of a blade and the inclined surface of thesharpened edge of another blade. Such a gap may reduce the cuttingquality of the cutting blade, so that it is necessary to remove such agap from the cutting blades set on the wood block. In order to removesuch a gap from the junction between the cutting blades, a cutting blade1, of which the end meets the side surface of another blade 1, isprecisely machined at the end in order to form a tip capable ofsubstantially meeting the inclined surface of the sharpened edge of theother blade 1. Therefore, any gap is removed from the junctions betweenthe cutting blades 1 which are commonly set on a wood block.

[0107] Industrial Applicability

[0108] As described above, the present invention provides a device forforming a cutting blade for prints. The blade forming device of thisinvention forms cutting blades by appropriately bending and cutting ametal strip into desired blades through integrated work regardless of adifference in the size of metal strips. The device is also provided withchangeable jigs, thus being capable of forming bridge notches havingdifferent intervals and configurations. The device has one verticallymovable bending pin and one swing cutter. The bending pin is capable ofquickly bending a metal strip into a desired configuration, while theswing cutter finely and precisely cuts the metal strip into cuttingblades.

[0109] Another advantage of this invention resides in that the devicequickly produces high precision cutting blades, thus improvingproductivity and reducing the cost of the cutting blades.

[0110] Although the preferred embodiments of the present invention havebeen disclosed for illustrative purposes, those skilled in the art willappreciate that various modifications, additions and substitutions arepossible, without departing from the scope and spirit of the inventionas disclosed in the accompanying claims.

1. A device for forming a cutting blade for prints, comprising: a striproll unit having a sufficient amount of metal strip and being rotatablein a direction by intermittent drive means, thus supplying the metalstrip at a constant rate; two guide blocks provided in front of saidroll unit and adapted for guiding the metal strip from the roll unit; abridge cutting mold detachably and selectively installed at one side ofthe two guide blocks and used for forming bridge notches on the metalstrip, said bridge cutting mold comprising: a housing having both astrip passing hole and a jig guide slot, said strip passing holeperpendicularly meeting said jig guide slot; and a spring-biased jigmovably positioned in said jig guide slot, thus selectively and quicklymovable in the jig guide slot so as to form the bridge notches on themetal strip passing through the strip passing hole; a guide bendingblock provided in front of said bridge cutting mold and having a bendingnozzle used for distributing the metal strip from said bridge cuttingmold; a guide bending pin vertically positioned in front of said bendingnozzle, said bending pin being vertically and controllably movable androtatable in opposite directions, thus bending the metal strip from thebending nozzle into a desired pattern; a carrier movably held by twovertical guide rails standing in front of said bending pin, said carrierbeing movable downward under the guide of the two guide rails by a firstcylinder actuator in response to a bending process ending signal; astrip holder mounted to a bottom center of said carrier and adapted forvertically holding said metal strip from the bending pin; a swing cutterhinged to said carrier and positioned in front of said strip holder,said swing cutter being selectively rotated by a second cylinderactuator in accordance with a detected angle of the metal strip, thusbeing positioned at a cutting process waiting position; a table providedwith a slot for selectively holding a lower end of said strip holderwith the carrier fully descending, said table also having a horizontalguide groove in front of said slot; and a movable piece slidably set insaid horizontal guide groove of the table and having a locking slot at atop surface, said movable piece being quickly movable in oppositedirections in said guide groove with a lower end of said cutter beingheld by the locking slot of the movable piece, thus quickly cutting themetal strip into cutting blades.
 2. The device according to claim 1,wherein a removable compression roller is provided at an appropriateposition relative to said guide blocks, thus pressing said metal stripfrom the guide blocks at an appropriate pressure and allowing the metalstrip to move while maintaining a height.
 3. The device according toclaim 1, wherein said bending block is changeable with another one inaccordance with a size of said metal strip and is vertically anddetachably held by top and bottom plates in a way such that the bendingblock is horizontally aligned with a strip outlet of the two guideblocks.
 4. The device according to claim 1, wherein a plurality ofhorizontal and vertical guide rollers are arranged between the two guideblocks, thus guiding the metal strip from the strip roll unit inhorizontal and vertical directions, respectively.
 5. The deviceaccording to claim 1, wherein said spring-biased jig is primarilyinserted into the jig guide slot of the bridge cutting mold with bothsides of a front edge of said jig being held by said guide slot andsmoothly slides in the guide slot while being separated from a side wallof said guide slot when the jig is quickly and fully inserted into themold so as to form the bridge notches on the metal strip.
 6. The deviceaccording to claim 1, wherein said jig is small-sized and repeatedlypunches the metal strip while finely moving the metal strip, thusenlarging a width of each of said bridge notches.
 7. The deviceaccording to claim 1, further comprising cutting means for transverselyforming a vertical bending slot on a side surface of the metal strip ora V-notch on a sharpened edge of said metal strip, said cutting meanscomprising: a motor-operated up/down cylinder actuator; a stepping motormounted to a piston shaft of said up/down cylinder actuator andselectively activated in accordance with an up/down motion of the pistonshaft of the up/down cylinder actuator; and a grinding wheel fixedlyfitted over a drive shaft of said stepping motor and selectivelyoperated by the motor, thus forming the vertical bending slot or theV-notch on the metal strip.
 8. The device according to claim 1, furthercomprising cutting means for transversely forming a vertical bendingslot on a side surface of the metal strip, said cutting meanscomprising: a motor-operated up/down cylinder actuator; and a biteaxially mounted to said up/down cylinder actuator and selectivelyactivated in accordance with an up/down motion of a piston shaft of theup/down cylinder actuator, thus forming the vertical bending slot on themetal strip.
 9. The device according to claim 1, further comprisingmarking means for forming a bending point on said metal strip prior to amanual bending process, said marking means comprising: two numericallycontrolled and removable marking jigs positioned at both sides of themetal strip so as to be directed toward the strip, each of said twomarking jigs being operated in conjunction with a cylinder actuator andselectively and quickly biased toward the metal strip, thus forming topand bottom bending points on each side surface of said metal strip. 10.The device according to claim 1, wherein said bending pin has agenerally semicircular cross-section with opposite side surfaces beingconvex and concave, respectively and also has two notches along each ofopposite rounded corners between the convex and concave surfaces, saidbending pin being positioned it a way such that the pin comes intocontact with the metal strip at either of the opposite rounded cornerswith the two notches being respectively positioned around upper andlower edges of the metal strip.
 11. The device according to claim 1,wherein said bending pin is held by two pin guiders at upper and lowerportions when the pin is fully moved upward so as to bend the metalstrip, so that the pin is protected from being unexpectedly bent duringa bending process.
 12. The device according to claim 1, wherein saidstrip holder consists of two holding blocks with an adjustable verticalslit being formed between the two holding blocks, said vertical slitbeing adapted for holding the metal strip and being sharpened into aV-shaped configuration at a web, thus being capable of firmly holding asharpened edge of the metal strip, said vertical slit being alsochamfered at each edge of a mouth, thus being capable of effectivelyguiding the metal strip into the vertical slit even when the metal stripfrom the bending nozzle fails to be precisely aligned with the verticalslit.
 13. The device according to claim 1, wherein a lower portion ofsaid swing cutter narrows in the middle with an inclined cuttingsurface, thus forming a narrow waist with an inclination angle of β, sothat when the cutter is rotated in order to cut the metal strip, thecutter primarily comes into contact with a lower portion of the metalstrip at said inclined cutting surface and cuts the metal strip from thelower to the upper edge.
 14. The device according to claim 1, whereinsaid swing cutter is moved to the bending process waiting position underthe control of a proximity sensor, said sensor being capable of checkinga finally bent portion of the metal strip prior to outputting a startsignal to the second cylinder actuator for the cutter.
 15. The deviceaccording to claim 1, wherein said cutting blade is machined at an endin order to form a tip capable of substantially meeting an inclinedsurface of a sharpened edge of another cutting blade, thus removing anygap from a junction between the two cutting blades when the two bladesare commonly set on a wood block with the ends of the blades closelymeeting each other at an angle.